The determination of the audience for electronic media broadcasts, such as radio or television, is of significant value and importance. The measured audience size reflects broadcast popularity, and creates a yardstick by which programming penetration into a market can be determined. Advertising rates associated with a broadcast are often a function of expected audience size. The more heavily watched or listened to a program, the greater the level of revenues that can be generated from advertising associated with the broadcast.
There have been numerous attempts to develop systems and methodologies for the determination of an actual audience, typically by attempting to monitor the activities of a particular audience segment and extrapolating that data to a more general audience.
At the most basic level, an audience member is directed to maintain a written log of his or her listening or viewing habits. The entry of such log data is often viewed as being a significant burden to the participant, and such logs are typically subject to large errors, inaccuracies and time gaps, resulting from both intentional and unintentional actions by the participant.
Monitoring systems which do not require active data recordation by the audience members are obviously preferable. Often, such monitoring systems are associated with a particularly adapted receiver apparatus, such as a television, located in the participant's home. Added circuitry within the receiver is capable of making a record of the particular broadcast to which the receiver is tuned, typically through reference to the audio portion of the broadcast. When an audience member wearing an associated monitoring device is in the presence of the receiver, the identity of the individual is transmitted to the receiver and is associated with the identity of the broadcast station to which the receiver is tuned, along with a record of the time interval in which the individual is present. Subsequently, the nature of the broadcast at the time of interest must be determined and correlated with the listener identification.
Other systems utilize portable receivers carried by the listener. In U.S. Pat. No. 4,626,904, for example, The audio portion of a television broadcast received by a television receiver is rebroadcast as a radio signal which is received by a portable receiver/headphone system worn by a viewer. Receipt of the signal causes an identification signal associated with the headphone system to be transmitted to a monitor unit. The monitor records the identity of the headphone, the duration of headphone activation, and with the channel to which the television is tuned.
Other portable receiver systems, as exemplified by the systems in U.S. Pat. Nos. 4,677,466 and 4,955,070, among others, provide for processing of the received signal to determine its identity, and create a time stamped log of the broadcast received. The broadcast can be identified in various manners, including by comparing the broadcast to reference signals or by decoding identification information present in the signal. The processed data retained by the receiver may be subsequently downloaded and transmitted to a remote facility.
While systems based upon a portable receiver and processor worn by the audience member are capable of providing a fairly accurate log of the signal to which the audience member is exposed, they are subject to significant limitations, in that only a limited number of broadcast signals or stations can be analyzed. Each of the receivers must be programmed with the necessary comparison data for a particular set of stations. This limits the universality of such a system. In addition, the computing power needed to do such analyses, particularly on a near real-time basis, severely limits the portability of the units as well as creating significant power requirements.
It is accordingly a purpose of the present invention to provide a remote sensing system capable of processing and evaluating broadcast audio signals perceived by an audience member.
A further purpose of the present invention is to provide such a remote sensing system in which a device carried by audience member is small, inconspicuous, and is of a universal character, capable of performing in a variety of locales.
Still a further purpose of the present invention is to provide a remote sensing system in which the processing of data is performed by a master unit, such that a plurality of carried devices can be associated therewith.